This invention relates to an improved output shaft arrangement for deep reduction and splitter boxes in transmissions.
Prior art heavy duty manual transmission have at least one auxiliary box utilizing an input and output shaft with an intermediate shaft, or quill shaft, interposed between the shafts. Bearings are required to support the intermediate shaft. A synchronizer and a clutch collar are used as engagement mechanisms for engaging the gears within the auxiliary boxes. Both the synchronizer and clutch collar have opposing ends with teeth for engaging the gears and coupling them to the shafts. Typically, one engagement mechanism is supported on the output shaft while the other engagement mechanism is supported by the intermediate shaft. However, this arrangement adds cost and reduces reliability as a result incorporating the intermediate shaft and bearings.
These arrangements have been used for splitter boxes as well as deep reduction gear boxes. To better appreciate the present invention, a prior art auxiliary box 20 is shown in FIG. 1. The auxiliary box 20 includes an input shaft 22 having an axis of rotation A and extends between a first end 24 extending into the auxiliary box 20 for transmitting power to the auxiliary box 20 for increasing or reducing the torque from the input shaft 22. The auxiliary box 20 also includes an output shaft 26 coaxial with axis A for transmitting power out of the auxiliary box at either an increased or reduced torque. Interposed between the input 22 and output 26 shafts and coaxial with axis A is an intermediate shaft 28, or quill shaft. A first gear 30 is supported by the input shaft 22 at the first end 24 which is adjacent the intermediate shaft 28. A second gear 32 is supported by the intermediate shaft 28 and a third gear 34 supported by the output shaft 26. The auxiliary box 20 further includes a pair of countershafts 36 on either side of the input 22, intermediate 28, and output 26 shafts, which allows more power to be transmitted through the auxiliary box 20. Each countershaft 36 has fourth 40, fifth 42, and sixth 44 gears affixed to a shaft 46 for engaging the first 30, second 32, and third 34 gears, respectively. Additional countershafts 36 may also be used.
To selectively transmit power through a particular set of gears, the auxiliary box 20 includes a synchronizer 50 and a clutch collar 52. The synchronizer 50 is supported by the intermediate shaft 28 for engaging one of the first 30 and second 32 gears. The clutch collar 52 is supported by the output shaft 26 for engaging one of the second 32 and third 34 gears. The synchronizer 50 and clutch collar 52 are splined to the shafts 28, 26 in slip-fit relation, that is, they are free to move axially when actuated but are not permitted to rotate relative to the shafts 28, 26. The second 32 and third 34 gears are axially located on the intermediate 28 and output 26 shafts and free to rotate about the shafts when the synchronizer 50 and clutch collar 52 engages neither of the second 32 and third 34 gears. Mechanically actuated shift forks (not shown) engage and manipulate the synchronizer 50 and clutch collar 52 along axis A to effectuate an auxiliary box 20 gear shift.